An articulated mechanism for use as an articulated arm of an industrial robot, for example, includes a plurality of arms interconnecting articulations having respective fluid pressure angular displacement motors for angularly displacing the arms relatively to each other. A plurality of pipes are positioned in the arms, respectively, for supplying a fluid under pressure to the articulations, and a plurality of oil passages are disposed in the articulations, respectively, and branched from the pipes, respectively, to supply the fluid under pressure to the fluid pressure motors.